Implications of New Physics in Semileptonic \(b \rightarrow c \tau \bar{\nu }\) Transitions

several indications of lepton non-universality observable have been perceived in semileptonic B meson decay processes, both in the neutral-current ( \(b \rightarrow s ll \) ) and charged-current ( \(b \rightarrow c l \bar{\nu }_l\) ) transitions. We execute it through a model-independent analysis in order to probe the nature of new physics. Taking into consideration the most general effective Hamiltonian, we scrutinize \(\Lambda _b \rightarrow \Lambda _c \tau \bar{\nu }_\tau \) , \( B_c^+ \rightarrow \eta _c \tau ^+ \nu _\tau \) , and \( B \rightarrow D^{**} \tau \bar{\nu }_\tau \) (where \(D^{**} = \{D^*_0, D_1^*, D_1, D_2^*\}\) are the four lightest excited charm mesons) processes, in the presence of new physics(NP). We perform a global fit to different sets of new coefficients, making use of the measurements on \(R_{D}\) , \(R_{D^{*}}\) , \(R_{J/\psi }\) , \(P_{\tau }^{D^*}\) and the upper limit on Br( \(B_c^+ \rightarrow \tau ^+ \nu _\tau \) ). We then inspect the effect of constrained new couplings on the branching ratios (BR), forward-backward asymmetry parameters (AFB), lepton non-universality ratios (LNU), lepton and hadron polarization asymmetries of these decay modes.